The invention relates to a television signal processing unit which provides monitoring to detect erroneous operation of one or more of the circuit sections thereof. Such a processing unit may be, for example, for processing the red, green or blue signal of a HDTV television camera in a HDMAC transmitter. The term "television signal" is herein to be understood to refer to a component video signal (for example, a red signal, a colour difference signal, a luminance signal, etc.), or a processed component video signal, or any of a plurality of combined video component signals.
The paper "HD-MAC Uebertragung mit 140 MBit/s" by M. Gendsior, J. Wenger, J. Witzany, NTZ, Vol. 42, 1989, no. 9, pp. 638-647 describes, for example a processing unit for a HDMAC television signal being shown in FIG. 2 thereof on page 640. This Figure shows a coder for generating HDMAC signals and a decoder for decoding the HDMAC signals.